Sewing machine and method of operating the same



May 15, 1945. J. E, WERTZ 2,376,216

SEWING MACHINE AND METHOD OF OPERATING THE SAME Filed Nov. 21, 1942 4 Sheets-Sheet l INVEN TOR. M55 .E M7? T2 May 15, 1945. .1. E. WERTz 2,376,216

SEWING MACHINE AND METHOD OF OPERATING THE SAME Filed Nov. 2l, 1942 4 Sheets-Sheet 2 F|G.I[[.

WER-rz 2,376,216A SEWING MACHINEAND METHOD OF OPERATING ATHE SAME I May 15, 1945.

Filed Nov. 21, 1942 4 Sheets-Sheet 5 m m E E mm. WW i E m \m\ Nw M www Mh A mw Nw u a Ear.,

May 15, 1945. J.E.wER1-z 2,376,216

SEWING MACHINE AND METHOD OF OPERATING THE SAME Filed Nov. 2l, 1942 .4 Sheets-Sheet 4 FIG. YH,

FIGAZL INVENTOR,

Patented May 15, 1945` vSE'WIN G MACHINE AND METHOD' 0F OPERATIN THE SAME James E. Wertz, Charlotte, N. C., assignor to :Union Special Machine Company, Chicago, Ill.,

a corporation of Illinois Application November 21, 1942, Serial No. 466,418

(c1. i12-21s) 13` Claims.

This invention'relates to a lockstitch'sewing machine having a rotary hook comprising a rotating component with ajraceway and a stationary component, forming a bobbin holder, with a rib in bearing engagement with the raceway. It is concerned more specifically with a method of and an arrangement for increasing the permissible speed of Aoperation of machines,

of this character. Toward this endy a vnovel method and means are provided for lubricating the'raceway of the hookand for simultaneously cooling the hook. l

A primary object of the invention has been to provide a simple and inexpensive way of effectively delivering an appropriate amount of lubricant to the raceway of a rotary hook of the character' indicated and simultaneously directing a blast of cooling air against thehookv to `dissipate heatgenerated in the corurse of operating' the same. In the high speed operation of sewing machines, in accordance with the present trend toward maximum output for each machine, considerable heat is normally developed 'due to friction between the bearing surfaces of the rotating and stationary components lof the hook. "Ihis friction may be reduced to a minimum by effective lubrication of the hook raceway. However, even with proper lubrication, the rotation of the hook at speeds in the'neighborhood `of^10,000 R. `P. M. tends to develop heat which may prove objectionable if not dissipated. By directing' coolingl air against the vhook .during operation of the machine, in addition to appropriate lubrication, the machine is rendered highly eici'ent and danger of overheating the hook is substantially eliminated. I l

An important feature of the inventionv is the provision of means, under directv control of the sewing machine, for dischargingagainst an appropriate portion of the rotaryvhook a stream or blast of air laden withfa mist .or finely divided particles or droplets of lubricating oil. .The air.

for this purpose is derived from. any suitable source of supply, such as a compressor at a distant point, and means arel provided for periodically interrupting the lloW of air at high fre- -quency` and delivering a drop or small quantity of oil during the brief interruptions of the air flow into position for subsequent introduction into and atomization by the air-stream. There is thus provided an interrupted flow of the stream or blast of air containing the ilnely divided spray of oil butthe frequency of the interruptions is suchthat the ellect of a continuous blast .is produced. "Y

VAnother feature of the invention is the provision of simple but effective means for automatically introducing a desired amount of lubricant into the air stream.

Other objects, features and advantages of the 'invention will appear from a detailed description-of an illustrative form of the same which dicated in horizontal section for purposes of bet` ter illustration.

Fig. IV is an enlarged, transverse, sectional view through the base of the machine, taken along the broken line IV-IV of Fig.- lII.

. Fig. 'V is a view similar to Fig. 1V but showing the partsin a different position, assumed in the course of operationv of the machine.

' Fig. VI is a detail view, vin elevation, showing the means for introducing the lubricant into the air stream.

Fig. VII is" an elevational View of the same devicesv as seen from the leftin Fig. VI.

Fig. VIII isa top plan view of the same devices, as indicated by the line VIII-VIII in Fig. IV, and

Fig. IX is a transverse section along the linev IX-IX 0f Fig. IV.

For purposes of illustration, the invention has 2,113,572, granted on April l2, 1938. The machine comprises a frame having a base portion I0, a vertical standard II, and an overhanging arm projecting laterally from the upper end of the standard and terminating with a needle head portion I2. Power is supplied to the machine from any suitable source by means of a belt (not shown) connected with a combined hand wheel and pulley i3 secured to the end of a main drive shaft I4 which extends longitudinally of the overhanging arm. f Suitable connections are provided from theshaft I4 for vertically reciprocating a needle bar I5 mounted in the needle head. This bar carries at its lower end one or more needles I5a. Also mounted in the needle head, for vertical movement, isA a presser bar I6 carrying at its lower end a, presser foot Il. This bar, n as will be understood, is spring-urged downwardly to retain the presser foot yieldingly against the work supporting surface of the base I and in cooperation with suitable work feeding devices within the latter.

Through appropriate gearing within the standard, power is also transmitted from the shaft I4 to a gear lsecured to the endof a shaft I9 suitably journaledwithin the base of the machine and extending lengthwise thereof. A gear 20 secured to the shaft I9, intermediate its ends, and meshing with a pinion 2| secured to a hook shaft r.22, mounted in a bearing 23 in the base, servesto, drive the hook shaft at double the angular speed of the shaft I9. In this way a rotaryfcomponentl` 24 of a rotary hook unit is driven atdoublethe frequency with which the needle I is reciprocated in the formation of stitches. Within thev rotary component of the hook there is mounted a stationary component 25 serving asa=bobbin7 holder, the latter being held against rotation .in any` suitable and well known manner. Itwill beA understood that the rotary hook is of a typehav.- ing a raceway in the innersurface of thecircumferential wall of the rotary componentv 24, `this raceway` receiving, and being in bearing engage.- mentrwith, ribs projecting from the peripheryof the. bobbin holder 25. As indicated in Fig. III,

` the main lbody ofthe rotary component has-one or more openings 26 in its wall, at or adjacent its base, through which the bottom or inner end.ofthebobbin case is exposed. v

Connections are also provided from thev shaft I9,.or` imparting a four-motion operation `to a feed -dog 2.1 which cooperates with thepresser foot I1.in.the manner hereinabove mentioned. This `feed dog is mountedupon a feed bar ,28 lwhichr is given its lifting and lowering movements: by means, ofan eccentric or crank pin 29,-atthefend of theshaft I9 `)and is given its feeding rand,:returnl movements -by an eccentric secured to. thefshaft I9'andy cooperating Witnan eccentric strap 39. For. further details as to the construction.: andi operation of the feed mechanism, and alsoithee stitchforming devices, referencemay behad to the above-mentioned Christensen etal. patent..

Turning now to the devices for delivering to= therotary hook a blast,l or series of intermittent blasts, ofl cooling air containing nely'. divided particles of asuitabl'e lubricant, referencemay be` had particularly to4 Figs, III toIX, inclusi-ve.

The air may be received through a hose Simons-` nected with'anysuitable; source of supplyL of;I air under pressure. It may, for example; beacon nected Withthe usual .airline to be found iti-a mill or it may otherwise be connected with acorn pressor unit or a tankcontaining air underpres-n sure.- cooled somewhat before it4 is` deliveredlthrough the hose 3l. Thishose is passed throughasmall opening in a pan or. .casing 3Ia carriedby the supportingtable for the machine. Anipple- 32- servesgtoconnect the. hose with a valve-33which may `be manually operated to control thesupply Ufairxtothenmachine. The outlet side oftheV valve 33lis-connected with a threadedistem-34iof a-.downwardlyextending branch 35`of v'a' combined' mixing: or atomizing chamber and automatic valveK unit-.36., The lattermay convenientlyA be provided" witha, laterally extending bracket portion` or base" 3'! adaptedto be attached by. screws or the likeW to lthe under,I surface of the top ofthe base ofthe machine.'v The'funit` 36; 'has amain'cylinder or chamber portionz38 withthe interior of which-abore or .passage 39,1v extending axially-- of the branch'-` If Va compressor. is4 used they air should-be- 35, is adapted to communicate. Within the chamber 38 there is mounted for reciprocation, with a relatively close nt, a reciprocating plunger or valve member 49. The outer end of the latter is pivotally connected with an eccentric strap 4I arranged to cooperate with an eccentric 42 securedto `the shaft I9. Thus, .uponreach cycle of operation. of. the, machine the I valve member 40 will be reciprocated.

Valve member 40 is provided with a port 43 which at times isalined with the passage 39, as shown insFig. V; and at times is displaced so as to close olf the interior of the chamber with respectto.; the .,passage; 39, as shown in Fig. IV.

: When thetpori-,LLi-S-.1alined with the passage, air

del-ivered'througlithe hose 3| will be carried into theeinterionof:thachamber 38 which constitutes a mixing compartment. A recess 45 in the inner end-*offthevalve member 49 forms a part of this compartment.. Airdelivered. into the mixing compartmentlisdischarged through an outletfi.. having`A screw-threaded 1 engagement with an exe4 tension4'I`of,.the.chamber 38. The outlet.,46isf connected'byfacoupling.48 with a tube or pipe-.49.. which.servestoonveylthe air to a point adjacent. therotary; hook.. The. discharge end 59 ofthe tubeis,preferablylattened and is so disposed as.

to` direct theV airat anangle against the inner orrear surface offtherotary component of thehook. As ,the hook rotates, apart-of the air so discharged? will pass through the opening 26.:and strike -the base. ofthe .bobbin .holder To increase the, effectiveness. ofthe coolingf-air: and bringl aboutproper. lubrication .of the hook; raceway.simultaneouslyl with the cooling action,. provision. isfmadeifor-,introducing oil into theair.. in small,.measured.or.regulated amounts and thisisaccOmplisl-ied in suclna way as-.to atomize the oil.w Eorlthis purposeltheoil .is supplied by gravity, from .an .oil cup` 5I suitably` mounted on .the base, of. the lmachine and having. the usual.,regulating meansi I a. ,andfshut-.oi means. 5 I b `for controlling, the -owlof. theoil. The cup. isl secured'to. the.

base.-l of fthe-machine .byy a screw-threaded Y stem or. nipple 52. having threaded'` engagementv with anopening inathe. base. Beneath ,the top. of the: machine. base. the. :stemiis connected by l a nipple.

53\with.a tube 54,which.serves,to convey; the;

oil `,toa cap, 55 .secured to .an extension -56 formingpartof the combinedmnitdnereinabovementioned;v 'I'heextension. Sliffis` provided. With: an upwardly, inclined 11 passage.: 5:1 f: which is.;l substantially,I tan gent to. fthe. periphery; ofrthe :valvefmember: and.; terminates-directly.'overy the axis ofthe latter;

A diametrically extending port 58 inthe valve memberzisadaptedt times ,to` communicate with the:uppern-endgofxthepassage 5J; indicatedy 1 in. Figs. IV and: IX; and.: ati: other `'timesx is adapted i to: be; outzoti registration :with4 the f passage 5T; as.` indicatediinnFig. vV; Ati the lowerfend offtlie port :58ia small 1 tube .595 serves to -place' theporti incommu-nication witlrthe pocketor recess in fthe.` valvefmember: Thus, Whenever the valve memberiis-inlthe^position indicated in=Fig; IV, a

drop. or; small, l measuredvz quantitygfof oi-l vvllbe delivered`- through" the-passage 51'; portr' and" tube =591`to a pointljustabove the4 port--43s As' the valve-member iS-Shifted'from the left into' the Fig.

VJ position,- however; communicationA with the which will be drawn, by the suction action of the hand,:i.,-e., between successive seam formations,y

the 4supply of oil will preferably be cutoffby the i valve 44l) and simply a continuous blast of cooling air will be directed against the hook. This may be insured by, so timing the operationof the parts thatthe valve will assume the Fig. V.' position whenV `the needlev is in its uppermostposition.

Care is, usually taken,l to stop the-machine, be-

tween. successive seam formations, with `the-needle substantially `at the'top of its stroke. If'desired, therelation between the plunger 40, the-,port 43 andpassage 5I may be such that when vthe-,machine is stopped with the needle at thetop'of its stroke, both the`v air and oil lines will be cut-off. Thestrpke of the plunger may be increased somewhatfor this purpose. When .the machine is' to be leftidle for a relatively long period, as at the close of the day, the valve 33 should beturned to its closed position to completely cut-off the supply ofsairiand the control member 5Ib on the oil cup maybe turned to cut-off the supply of oil, v

.The operation of the machine, and particularly the hook cooling and .lubricating devices, is believed to be clear from the foregoing. Through the reciprocation of the valve member 40, by the operation of the eccentric 42, a rapid succession of air blasts is created, each serving to atomize a drop or small quantity of oil delivered to a point just above the port 43 after each blast. The atomized lubricant and cooling air are delivered against the base of the rotary component of the hook and, due to the large open space 26 at this point, a good'part of the air and oil will be discharged into the interior of the rotary component and will eventually reach the raceway, dueto centrifugal force, and will lubricate the bearing surfaces on the rotary and stationary compoy nents.

While a .preferred form of the invention has been described in considerabler detail, it will be understood that numerous changes may be made in the construction and arrangement of the various parts without departing from the lgeneral principles and scope of the invention.

I claim: 1. In a, lockstitch sewing machine a rotary hook having rotating and stationary components in component, a mixing chamber, means for delivering air under-pressure to said chamber, means for delivering oil to said' chamber, valve means for controlling the intermittent delivery of air driving means for controlling saidavalve means, and a conduit for delivering the mixture of air and'oilfrom said chamber to said rotary hook.

3. In a lockstitch sewing machine' a rotary hook having rotating vand stationary components in bearing engagement, means for driving the rotary component', a mixing chamber, means yfor delivering air lunder pressure to said chamber,

meansfor delivering oil to said. chamber, valve means for controlling the delivery of air and'oil -to said chamber, meansoperated by said driving means for controlling said .valve means to admit the air at one point and oil at another point in the cycle ofthe drivingmeans and thus .alternately to said chamber, and a conduit for delivering the mixture of air and oil from said chamber to said rotary hook.

4. In a lockstitch sewing machine a rotary hook having rotating and stationarycomponents in bearing engagemenameans for driving the rotary component, a mixing chamber, means for delivering air under pressure to-said chamber, means for delivering oil to said chamber at a lpoint adjacent the point of delivery of the yair thereto, means operatedby said driving means for Acontrollingr the intermittent delivery of air and oil to said chamber, and a con'duit'for delivering the mixture of air and oil from said cham,- ber tosaid rotary hook under the force ofsaid air. f

`5. In a lockstitch sewing :machine a,v rotary hook having rotating and stationary components in bearingv engagement, means for driving the rotary component, a mixing chamber, means for delivering'air under pressure to said chamber,

' means'for delivering oil ito said chamber, a reciprocatory plunger arranged to control the alternate introduction of air and oil into said chamber, connections from said driving means for operating said plunger, and a conduit for delivering the mixture of air and oil from said chamber to said rotary hook.`

6. In a lockstitch sewing machine a rotary hook having rotating and stationary components with surfaces in bearing engagement, means for driving the rotary component, an atomizing chamber, means for directing a streamv of air under pressure into said chamber, means operated by said driving means for periodically interrupting the flow of air into said chamber, means for delivering a small quantity of oil into the path of said air stream during each period of interruption of ow oi the air, and means for delivering the resulting stream of atomized oil to the hook for cooling and lubricating the same.

7. In a -lockstitch sewing machine a rotary hook having rotating and stationary components with surfaces in bearing engagement, means for driving the rotary component, an atomizing chamber, means' for directing a stream of air under pressure into said chamber, means controlled by said driving means for intermittently introducing small quantities of oil into the path of said stream for atomization thereby within said chamber, and means for delivering the resulting stream of atomized oil to the hook for cooling and lubricating the same.

8. In a locksttch sewing machine a rotary hook having rotating and stationary components vwith surfaces in bearing engagement, means for and oil tosaidchamber,` means operated by said' hoolnshavingftrotating andlstationarytcomponents- 10 withsurfaces. in bearing engagement; means for driving:` thev rotary component, n ant?. atoxn-izingY chamber;` ac-:vvalvemember associated: withvsaid; cnam-ber andsconnected with :saidg driving means* forV continuous;` operation, saidA member; being 15s placed inv.- each of tworpositions;uponceachzcycie,

of x operations'4 ofA the machine,V means for i intro',- ducing a small quantity ofoil into fsaid' .chamber each time =said;-,va1ve `rnemloeris in f. one of said positions;A .meansv for introducing air underpres-v 20.v

sure tinto,I said 1 chamber eaclrtime sa'id.va1ve membereis inzwth'ef other'of said positions; means. for: delivering-r` thev resultingl mixturel of oil r. and airv to the-rotary@ hook-rv for'. cooling: and; lubricating the same;l

101 Iney a: lockstitch r sewing z machine a rotaryi hook'l having."rotating` ,and stationary-iV components with surfacesiin bearing engagement; .means forl driving the rotary component, an.' atomizin'gfchamben; means-for; delivering" air` under pres 30' sure from a remote source to said chamber: meansv control-ledgby'l said'todriving means for deiivering af regulated; small quantity ofL-oii into'. said chamber upon".` each cycle of"operation1l of the machine,4 the: arrangement@ beingcsuch' that 35 said oil is atomizedi by.. saidair; .andzm'ean'sffor delivering` the :atomized l oil Vunder their forcer;u ofi trolled by'fsadfdriving-J means-fior delivering a.. reguI-'ated,sma1l quantity Ii of; oil .byu gravity.. from said: rstoragemeansl into .f said'chamber'uponf each:v cycle;y ofoperation fof.y zthe; machine;y .thefarran'gementF beingfsuch:` that f'saidaoil'isf atomized; byisaid; air,.and meansffor` delivering: theatomizedtoilf under the: force of@ saidl' air` toisaidvrotarylhooki for coolingi and flubricatin'g thefxsam'e: u

121K method of sewingat'highispeedf onav iockstitch 1 sewing machinev having; a; rotary ibook.'v whichgcomprises I yalternatelyf:introducing anregu-v latedV quarititwY of f oil and 5' af. blast" offl airr'un'derf pressure into ai: miifzing'iziiine,l and'fdirecting. the'. resulting-lmixture.: bya means of" the: air: blast againstlti-refrotaryl hook to cool the'.F sam'eian'd` lubricateithe bearing-f surfacesvthereof;

13." A method of i sewing-fat' high sp'eed'on"a' iockstitcnffsewing:machinet-having a a ,-roftaryzihcok' Whichz\ comprises y introducing 1 al, regulated'lt quan tity; of-` oil into aconfnedmixingzone upon each cycl'efroff operation of the" machine; an'd1a1ter-- n'ateiyintroducing a biastoff cool lair' under'pres" sure intorsaid: zone Aand,Ysimu'ltan'eously disoharg#A l ing then-resulting i mixture of` Iairc: and;` loil against' the'arotarye hook. tofcool the same: an'd'lubricate the bearingtsurfacesf thereof.` 

